Steam-engine-valve-reversing gear



2 Sheets-Sheet` .1

May l, 1923.

F. R. STEVENS- STEAM ENGINE VALVE REVERSING GEAR Filed Ja'n. 2, 1925 WITNESSES May 1:1923;

F. R. STEVENS STEAM ENGINE VALVE REVERSING GEAR-v` 1923 2 sheecsfsheet 2 v Filed Jan. 2

FIG. 2

- is a view, partly in elevation and partly in etant ay l, l2.

"FREDERICK R. STEVENS, v0F

ST-ENGINEVALVEREVERSING GEAR.

.application aiea January 2, 1923. semi No. eieasa.

To all whom t may concern Be it known that I, FREDERICK R. STE- VENS, of Schenectady, in the county of Schenect'idy and State4 of New York, have in? vented a certain new and useful Improvement in Steam Engine Valve Reversing Gears, of which improvement the following is a speciication.

y My yinvention relates to power actuated mechanism for reversing the valves of steam engines, of the class or type inbwhichj-thev desired movements of the valve gear are transmitted thereto, from the motor, through the intermediation of a screw and nut. The object of my invention is to pro-'- vide `a mechanism of such type which shall be .of simple and inexpensive construction, and in the operation of which torque and side thrust will be eliminated, direct straight transmission of actuating power be eiected, complete protection. of' the screw and nut from dirt and grit adorded, and ample 'area of guide bearing and easy oiling facilities provided. The` improvement claimed ishereinafter fully set forth.

In the accompanying drawings.: Figure 1 longitudinal central section, of a steam engine valve reversing gear, illustrating an embodiment of my invention; Fig. 2, a similar view, taken at a right angle to Fig. 1', and on a larger scale, cii'the'left hand portion thereof, and; Figs. 3, 4 and 5, vertical transverse sections, on the lines@ a, b b 'and v c c, respectively, of Fig. 1.

V"forward thrust of the \,screw.g The 'back- In the practice of my invention, referring descriptivelv to the specific embodiment thereof which is herein exemplified, I provide a cylinder, 1,` having lateral brackets, 1a, l, on one side of its axis, for attachment to a suitable support. The rear end ofthe cylinder is closed by a head, 2, which is formed integral with a rearwardly projecting motor support, 2a.

A screw, 3, is gournalled, inl line axially with the cylinder, in athrust bearing, 3,

in the motor lsiipport,'2, being* held, .as against' longitudinal movement-by a collar, 3, formed or fixed upon' it,.'and abutting against a thrust member, 3", which, is:l secured in the cylinder 1, and receives the ward thrust thereof is received by ,the motor support, through the` interni i .ai ation i, of;

thrust washers, 3*. The screw is adapted to be rotated` by a motor, 4, of any suitable and preferred construction, to the shaft of whibh itis connected by a gear, 15, engaging pinions, 15, rotated by the motor; The 60 motor, which does not, in and of itself, form.. part of my invention, is rigidly securedr'to the motor support, 2a. The screw, 3,is en-l gaged by a nut, 5, which is made in two sections, connected by bolts, 5a, and nuts', 65

between which sections, liners may be interposed to permit'adjustinent for wear, and

a cover plate, 5", is secured to a housing, 7, hereinafter specified` The heads of the nut sections are of triangular form, as shown in 'Figs 3 and 4so as to enable them'to be.

readily assembled betweeny the ribs of the connecting member, hereinafter described, and rigidly secured in operation.

The nut, 5, which, in the rotation ofthe i screw, 3, in either direction, traverses lon-f gitudinally,l thereon, *is coupled to the reach rod, 6, which correspondingly moves the yvalve gear, (not shown),through the intermediation of a pin, 6, and an integral con- 80 necting member, comprising a nut housing, v

' 7, located at its rear'end, inwhilch-"housing the nutis secured to prevent it from turning` by va key; a cross head. 7", at its forward end having lugsto .which the reach i.

.rod Ais articulated by the pin, 6a; a sleeve, 7", extending rearwardly from' the cross head, and turned to a neat fit'in the cylinder, 1; and a plurality of ribs, 7, connecting the sleeve to the nut housing,'7. rlhe 90 i connecting'member provides a long and ample bearing,- which completely eliminates any angular thrust on the screw; l.3. A key way, 7 d, which. is cut in the top ofthe sleeve, 7", is engaged by a key, 1b, fixed im the cyl- 95 inder, 1, the sleeve being thereby prevented from turning in the cylinder. The key. 1".

`is fitted in a sleeve, 1, whichis screwed into the cylinder,f1, so as to be readily removable therefrom when-"desired, without removing ico the connecting member. from"l the cylinder, which construction materially facilitates assemblv and minoradjustments of the gear.

A filling hole isformedv in the top of the i cylinder, 1, and is closed by a plug, 1", which 105 .is perforated by a small air vent, to 'permit'. free .circulation of air when 'the reverse'gear is operated, and an' oilv drain cock, 1, is con` nectedrto the bottom of the cylinder, to per# 2 mit oil to be drained ofi' ,when desired.

The manually operated motor control.

verse lever in the cab, said rod being cou! pled to an arm,- l1,connected to the controlling valve and having ascrew thread, 10, on its inner end, engaging a sliding sleeve, 9, which is, in turn, engaged with the screw, 3.

The novel features which are characteristic of my invention, and of substantial im portance and value in practice, may be summarized as follows: (a), a cylinder which completely encloses 'the screw' by which movement is imparted tothe reach rod, so as to protect it from the access of dirt and grit; (b), the rectilinear disposition of all working members thereby minimizing angular thrust; (c), the provision of a connecting member having a long bearing in vthe enclosing cylinder which eliminates torque in the screw; and, (d), the construction of the cylinder and connecting member in such relation to the screw as to enable it to be continuously operated in a bath of oil. y

In the operation of the a pliance, the operator causes the reach ro to. be moved, by

the 'traverse of the nut and connecting* member, effected by the rotation of the screw by the'motor, to the position corresponding to the desired adjustment of the valve gear, and thereupon engages the handv reverse lever with the proper notch of its segment. rIhe movement of the members is then automatically stopped, by the closure of the actuating valve of the motor, through the connectingmeans above described.

.I claim as 'my invention and desire to secure by Letters Patent: 1.

1. In a steam en ine valve reversing gear, the combination o a cylinder, closed lat one end; a screw rotatable therein; a.' connecting member, fitting in said cylinder and e'ecting closure of the opposite end thereof, and

adrpted to be cou led to a reach rod; and ag nut, fixed in sai connecting mem-ber and engaged by the rew.

Vthe combination of an enclosing cylinder; a

head closing one end thereof; a screw, rotatable therein, in line axially therewith; a connecting member, fitting in said cylinder and effecting closure of one end thereof; means for coupling a reach rod to said member, in line axially with the cylinder; and a nut, fixed in the connecting member and engaged by the screw.

4. In a steam engine valve reversing gear, the combination of an enclosing cylinder; a head `closing one end thereof; a connecting member, movable therein, and effecting closure of the oppositev end thereof; a screw, rotatable in the cylinder; a nut, fixed in the connecting member and engaged by the screw; means for coupling areach rod to the connecting member; and means for supplying oil to, and withdrawing it from, the enclosing cylinder.

5. In a steam engine valve reversing gear,

vthe combination of an enclosing cylinder; a

ber and engaged by the screw; means for` coupling a reach rod to the connecting member ;'.and a-motor, connected to the cylinder i head, and geared tofthescrew.

6. In a steam engine valve reversmg gear,

the combination of a connecting member,

having a nut housing at one end, a closed ended cross head at the other end, and intermediate connecting ribs; and a two part nut, secured adjustably'in the nut housing,- and havlng an angular head, insertible and removable between the ribs of the connecting member.

FREDERKCK R. STEVENS.

Witnesses:

y BURTON-B. MILLS, "JOHN lL. STEELE. 

